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Charting library for Android compatible with API 8+(Android 2.2).
The newest version!
package lecho.lib.hellocharts.renderer;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Cap;
import android.graphics.PointF;
import android.graphics.RectF;
import lecho.lib.hellocharts.model.Column;
import lecho.lib.hellocharts.model.ColumnChartData;
import lecho.lib.hellocharts.model.SelectedValue.SelectedValueType;
import lecho.lib.hellocharts.model.SubcolumnValue;
import lecho.lib.hellocharts.model.Viewport;
import lecho.lib.hellocharts.provider.ColumnChartDataProvider;
import lecho.lib.hellocharts.util.ChartUtils;
import lecho.lib.hellocharts.view.Chart;
/**
* Magic renderer for ColumnChart.
*/
public class ColumnChartRenderer extends AbstractChartRenderer {
public static final int DEFAULT_SUBCOLUMN_SPACING_DP = 1;
public static final int DEFAULT_COLUMN_TOUCH_ADDITIONAL_WIDTH_DP = 4;
private static final int MODE_DRAW = 0;
private static final int MODE_CHECK_TOUCH = 1;
private static final int MODE_HIGHLIGHT = 2;
private ColumnChartDataProvider dataProvider;
/**
* Additional width for hightlighted column, used to give tauch feedback.
*/
private int touchAdditionalWidth;
/**
* Spacing between sub-columns.
*/
private int subcolumnSpacing;
/**
* Paint used to draw every column.
*/
private Paint columnPaint = new Paint();
/**
* Holds coordinates for currently processed column/sub-column.
*/
private RectF drawRect = new RectF();
/**
* Coordinated of user tauch.
*/
private PointF touchedPoint = new PointF();
private float fillRatio;
private float baseValue;
private Viewport tempMaximumViewport = new Viewport();
public ColumnChartRenderer(Context context, Chart chart, ColumnChartDataProvider dataProvider) {
super(context, chart);
this.dataProvider = dataProvider;
subcolumnSpacing = ChartUtils.dp2px(density, DEFAULT_SUBCOLUMN_SPACING_DP);
touchAdditionalWidth = ChartUtils.dp2px(density, DEFAULT_COLUMN_TOUCH_ADDITIONAL_WIDTH_DP);
columnPaint.setAntiAlias(true);
columnPaint.setStyle(Paint.Style.FILL);
columnPaint.setStrokeCap(Cap.SQUARE);
}
@Override
public void onChartSizeChanged() {
}
@Override
public void onChartDataChanged() {
super.onChartDataChanged();
ColumnChartData data = dataProvider.getColumnChartData();
fillRatio = data.getFillRatio();
baseValue = data.getBaseValue();
onChartViewportChanged();
}
@Override
public void onChartViewportChanged() {
if (isViewportCalculationEnabled) {
calculateMaxViewport();
computator.setMaxViewport(tempMaximumViewport);
computator.setCurrentViewport(computator.getMaximumViewport());
}
}
public void draw(Canvas canvas) {
final ColumnChartData data = dataProvider.getColumnChartData();
if (data.isStacked()) {
drawColumnForStacked(canvas);
if (isTouched()) {
highlightColumnForStacked(canvas);
}
} else {
drawColumnsForSubcolumns(canvas);
if (isTouched()) {
highlightColumnsForSubcolumns(canvas);
}
}
}
@Override
public void drawUnclipped(Canvas canvas) {
// Do nothing, for this kind of chart there is nothing to draw beyond clipped area
}
public boolean checkTouch(float touchX, float touchY) {
selectedValue.clear();
final ColumnChartData data = dataProvider.getColumnChartData();
if (data.isStacked()) {
checkTouchForStacked(touchX, touchY);
} else {
checkTouchForSubcolumns(touchX, touchY);
}
return isTouched();
}
private void calculateMaxViewport() {
final ColumnChartData data = dataProvider.getColumnChartData();
// Column chart always has X values from 0 to numColumns-1, to add some margin on the left and right I added
// extra 0.5 to the each side, that margins will be negative scaled according to number of columns, so for more
// columns there will be less margin.
tempMaximumViewport.set(-0.5f, baseValue, data.getColumns().size() - 0.5f, baseValue);
if (data.isStacked()) {
calculateMaxViewportForStacked(data);
} else {
calculateMaxViewportForSubcolumns(data);
}
}
private void calculateMaxViewportForSubcolumns(ColumnChartData data) {
for (Column column : data.getColumns()) {
for (SubcolumnValue columnValue : column.getValues()) {
if (columnValue.getValue() >= baseValue && columnValue.getValue() > tempMaximumViewport.top) {
tempMaximumViewport.top = columnValue.getValue();
}
if (columnValue.getValue() < baseValue && columnValue.getValue() < tempMaximumViewport.bottom) {
tempMaximumViewport.bottom = columnValue.getValue();
}
}
}
}
private void calculateMaxViewportForStacked(ColumnChartData data) {
for (Column column : data.getColumns()) {
float sumPositive = baseValue;
float sumNegative = baseValue;
for (SubcolumnValue columnValue : column.getValues()) {
if (columnValue.getValue() >= baseValue) {
sumPositive += columnValue.getValue();
} else {
sumNegative += columnValue.getValue();
}
}
if (sumPositive > tempMaximumViewport.top) {
tempMaximumViewport.top = sumPositive;
}
if (sumNegative < tempMaximumViewport.bottom) {
tempMaximumViewport.bottom = sumNegative;
}
}
}
private void drawColumnsForSubcolumns(Canvas canvas) {
final ColumnChartData data = dataProvider.getColumnChartData();
final float columnWidth = calculateColumnWidth();
int columnIndex = 0;
for (Column column : data.getColumns()) {
processColumnForSubcolumns(canvas, column, columnWidth, columnIndex, MODE_DRAW);
++columnIndex;
}
}
private void highlightColumnsForSubcolumns(Canvas canvas) {
final ColumnChartData data = dataProvider.getColumnChartData();
final float columnWidth = calculateColumnWidth();
Column column = data.getColumns().get(selectedValue.getFirstIndex());
processColumnForSubcolumns(canvas, column, columnWidth, selectedValue.getFirstIndex(), MODE_HIGHLIGHT);
}
private void checkTouchForSubcolumns(float touchX, float touchY) {
// Using member variable to hold touch point to avoid too much parameters in methods.
touchedPoint.x = touchX;
touchedPoint.y = touchY;
final ColumnChartData data = dataProvider.getColumnChartData();
final float columnWidth = calculateColumnWidth();
int columnIndex = 0;
for (Column column : data.getColumns()) {
// canvas is not needed for checking touch
processColumnForSubcolumns(null, column, columnWidth, columnIndex, MODE_CHECK_TOUCH);
++columnIndex;
}
}
private void processColumnForSubcolumns(Canvas canvas, Column column, float columnWidth, int columnIndex,
int mode) {
// For n subcolumns there will be n-1 spacing and there will be one
// subcolumn for every columnValue
float subcolumnWidth = (columnWidth - (subcolumnSpacing * (column.getValues().size() - 1)))
/ column.getValues().size();
if (subcolumnWidth < 1) {
subcolumnWidth = 1;
}
// Columns are indexes from 0 to n, column index is also column X value
final float rawX = computator.computeRawX(columnIndex);
final float halfColumnWidth = columnWidth / 2;
final float baseRawY = computator.computeRawY(baseValue);
// First subcolumn will starts at the left edge of current column,
// rawValueX is horizontal center of that column
float subcolumnRawX = rawX - halfColumnWidth;
int valueIndex = 0;
for (SubcolumnValue columnValue : column.getValues()) {
columnPaint.setColor(columnValue.getColor());
if (subcolumnRawX > rawX + halfColumnWidth) {
break;
}
final float rawY = computator.computeRawY(columnValue.getValue());
calculateRectToDraw(columnValue, subcolumnRawX, subcolumnRawX + subcolumnWidth, baseRawY, rawY);
switch (mode) {
case MODE_DRAW:
drawSubcolumn(canvas, column, columnValue, false);
break;
case MODE_HIGHLIGHT:
highlightSubcolumn(canvas, column, columnValue, valueIndex, false);
break;
case MODE_CHECK_TOUCH:
checkRectToDraw(columnIndex, valueIndex);
break;
default:
// There no else, every case should be handled or exception will
// be thrown
throw new IllegalStateException("Cannot process column in mode: " + mode);
}
subcolumnRawX += subcolumnWidth + subcolumnSpacing;
++valueIndex;
}
}
private void drawColumnForStacked(Canvas canvas) {
final ColumnChartData data = dataProvider.getColumnChartData();
final float columnWidth = calculateColumnWidth();
// Columns are indexes from 0 to n, column index is also column X value
int columnIndex = 0;
for (Column column : data.getColumns()) {
processColumnForStacked(canvas, column, columnWidth, columnIndex, MODE_DRAW);
++columnIndex;
}
}
private void highlightColumnForStacked(Canvas canvas) {
final ColumnChartData data = dataProvider.getColumnChartData();
final float columnWidth = calculateColumnWidth();
// Columns are indexes from 0 to n, column index is also column X value
Column column = data.getColumns().get(selectedValue.getFirstIndex());
processColumnForStacked(canvas, column, columnWidth, selectedValue.getFirstIndex(), MODE_HIGHLIGHT);
}
private void checkTouchForStacked(float touchX, float touchY) {
touchedPoint.x = touchX;
touchedPoint.y = touchY;
final ColumnChartData data = dataProvider.getColumnChartData();
final float columnWidth = calculateColumnWidth();
int columnIndex = 0;
for (Column column : data.getColumns()) {
// canvas is not needed for checking touch
processColumnForStacked(null, column, columnWidth, columnIndex, MODE_CHECK_TOUCH);
++columnIndex;
}
}
private void processColumnForStacked(Canvas canvas, Column column, float columnWidth, int columnIndex, int mode) {
final float rawX = computator.computeRawX(columnIndex);
final float halfColumnWidth = columnWidth / 2;
float mostPositiveValue = baseValue;
float mostNegativeValue = baseValue;
float subcolumnBaseValue = baseValue;
int valueIndex = 0;
for (SubcolumnValue columnValue : column.getValues()) {
columnPaint.setColor(columnValue.getColor());
if (columnValue.getValue() >= baseValue) {
// Using values instead of raw pixels make code easier to
// understand(for me)
subcolumnBaseValue = mostPositiveValue;
mostPositiveValue += columnValue.getValue();
} else {
subcolumnBaseValue = mostNegativeValue;
mostNegativeValue += columnValue.getValue();
}
final float rawBaseY = computator.computeRawY(subcolumnBaseValue);
final float rawY = computator.computeRawY(subcolumnBaseValue + columnValue.getValue());
calculateRectToDraw(columnValue, rawX - halfColumnWidth, rawX + halfColumnWidth, rawBaseY, rawY);
switch (mode) {
case MODE_DRAW:
drawSubcolumn(canvas, column, columnValue, true);
break;
case MODE_HIGHLIGHT:
highlightSubcolumn(canvas, column, columnValue, valueIndex, true);
break;
case MODE_CHECK_TOUCH:
checkRectToDraw(columnIndex, valueIndex);
break;
default:
// There no else, every case should be handled or exception will
// be thrown
throw new IllegalStateException("Cannot process column in mode: " + mode);
}
++valueIndex;
}
}
private void drawSubcolumn(Canvas canvas, Column column, SubcolumnValue columnValue, boolean isStacked) {
canvas.drawRect(drawRect, columnPaint);
if (column.hasLabels()) {
drawLabel(canvas, column, columnValue, isStacked, labelOffset);
}
}
private void highlightSubcolumn(Canvas canvas, Column column, SubcolumnValue columnValue, int valueIndex,
boolean isStacked) {
if (selectedValue.getSecondIndex() == valueIndex) {
columnPaint.setColor(columnValue.getDarkenColor());
canvas.drawRect(drawRect.left - touchAdditionalWidth, drawRect.top, drawRect.right + touchAdditionalWidth,
drawRect.bottom, columnPaint);
if (column.hasLabels() || column.hasLabelsOnlyForSelected()) {
drawLabel(canvas, column, columnValue, isStacked, labelOffset);
}
}
}
private void checkRectToDraw(int columnIndex, int valueIndex) {
if (drawRect.contains(touchedPoint.x, touchedPoint.y)) {
selectedValue.set(columnIndex, valueIndex, SelectedValueType.COLUMN);
}
}
private float calculateColumnWidth() {
// columnWidht should be at least 2 px
float columnWidth = fillRatio * computator.getContentRectMinusAllMargins().width() / computator
.getVisibleViewport().width();
if (columnWidth < 2) {
columnWidth = 2;
}
return columnWidth;
}
private void calculateRectToDraw(SubcolumnValue columnValue, float left, float right, float rawBaseY, float rawY) {
// Calculate rect that will be drawn as column, subcolumn or label background.
drawRect.left = left;
drawRect.right = right;
if (columnValue.getValue() >= baseValue) {
drawRect.top = rawY;
drawRect.bottom = rawBaseY - subcolumnSpacing;
} else {
drawRect.bottom = rawY;
drawRect.top = rawBaseY + subcolumnSpacing;
}
}
private void drawLabel(Canvas canvas, Column column, SubcolumnValue columnValue, boolean isStacked, float offset) {
final int numChars = column.getFormatter().formatChartValue(labelBuffer, columnValue);
if (numChars == 0) {
// No need to draw empty label
return;
}
final float labelWidth = labelPaint.measureText(labelBuffer, labelBuffer.length - numChars, numChars);
final int labelHeight = Math.abs(fontMetrics.ascent);
float left = drawRect.centerX() - labelWidth / 2 - labelMargin;
float right = drawRect.centerX() + labelWidth / 2 + labelMargin;
float top;
float bottom;
if (isStacked && labelHeight < drawRect.height() - (2 * labelMargin)) {
// For stacked columns draw label only if label height is less than subcolumn height - (2 * labelMargin).
if (columnValue.getValue() >= baseValue) {
top = drawRect.top;
bottom = drawRect.top + labelHeight + labelMargin * 2;
} else {
top = drawRect.bottom - labelHeight - labelMargin * 2;
bottom = drawRect.bottom;
}
} else if (!isStacked) {
// For not stacked draw label at the top for positive and at the bottom for negative values
if (columnValue.getValue() >= baseValue) {
top = drawRect.top - offset - labelHeight - labelMargin * 2;
if (top < computator.getContentRectMinusAllMargins().top) {
top = drawRect.top + offset;
bottom = drawRect.top + offset + labelHeight + labelMargin * 2;
} else {
bottom = drawRect.top - offset;
}
} else {
bottom = drawRect.bottom + offset + labelHeight + labelMargin * 2;
if (bottom > computator.getContentRectMinusAllMargins().bottom) {
top = drawRect.bottom - offset - labelHeight - labelMargin * 2;
bottom = drawRect.bottom - offset;
} else {
top = drawRect.bottom + offset;
}
}
} else {
// Draw nothing.
return;
}
labelBackgroundRect.set(left, top, right, bottom);
drawLabelTextAndBackground(canvas, labelBuffer, labelBuffer.length - numChars, numChars,
columnValue.getDarkenColor());
}
}